The present invention relates to wrenches and more particularly to a double-sided ratchet wrench having a one-way reversing mechanism which provides greater torque and durability in comparison with the conventional ratchet wrenches.
A typical ratchet wrench as shown in FIG. 1 includes a the handle 10, a ring 11 at one end of handle 10 into which an internal ratchet gear 12 disposes, a rectangular tip head 13 disposed at the center of the ring 11, a cylinder post 15 in the center of the rectangular tip head 13, a spring 151 biased in a peripheral recess of the post 15 with steel ball 152 at the outer end of the spring 151 and a pallet 14 pivoted between the internal ratchet gear 12 and the post 15. The pallet 14 has a pair of first and second toothed ends 141 and 142 engageable with the teeth of the internal ratchet gear 12 and a pair of notches 143 and 144 engageable with the steel ball 152. When the post 15 rotates counterclockwise, the steel ball 152 engages into the notch 144 so as to force the pallet 14 tilting at rightward that its second toothed end 142 engages with the ratchet gear 12. Since the internal ratchet gear 12 can only be racing counterclockwise in a predetermined span, it enables the tip head 13 to fasten a screw clockwise.
FIG. 2 shows another typical ratchet wrench which includes a handle 20, a ring 21 at one end of the handle 20, an external ratchet gear 22 integrated with a tip head 23 disposed into the ring 21, a spring biased steel ball 231 disposed in a lateral side of the tip head 23 for enabling the tip head 23 to engage with a box, an arcuate pallet 24 pivoted between the ratchet gear 22 and the handle 20 including a first and a second angled ends 241 and 242 and a pair of notches 243 and 244 which are engageable with a spring 26 biased steel ball 27 in a center bore 25 of the handle 20. When the pallet 24 is turned clockwise, its second angled end 242 engages with the ratchet gear 22 so that the gear 22 can only be racing clockwise to enabling the tip head 23 to fasten a screw counterclockwise. Contrarily, if the pallet 24 turns counterclockwise and its first angled end 241 engages with the ratchet gear 22 which can only be racing counterclockwise so as to enabling the tip head 23 to fasten a screw clockwise.
However, both the above ratchet wrenches have the following disadvantages:
a) it could not provide greater torque unless the pallet would be breakable; PA1 b) both the ratchet gear and the pallet will become weary and abraded after a certain period of use; PA1 c) structurally complicated; PA1 d) the ring becomes too heavy after the tip head engages with additional parts that causes the wrench inconvenient to operate.